Risk factors for the development of surgical site infection in bariatric surgery: an integrative review of literature

Abstract Objective: to evaluate evidence on risk factors for the development of surgical site infection in bariatric surgery. Method: integrative review. The search for primary studies was performed in four databases. The sample consisted of 11 surveys. The methodological quality of the included studies was assessed using tools proposed by the Joanna Briggs Institute. Data analysis and synthesis were performed in a descriptive manner. Results: surgical site infection rates ranged from 0.4% to 7.6%, considering the results of primary studies, in which patients underwent laparoscopic surgery. In surveys of participants undergoing surgical procedures with different approaches (open, laparoscopic or robotic), infection rates ranged from 0.9% to 12%. Regarding the risk factors for the development of this type of infection, antibiotic prophylaxis, female sex, high Body Mass Index and perioperative hyperglycemia are highlighted. Conclusion: conducting the integrative review generated a body of evidence that reinforces the importance of implementing effective measures for the prevention and control of surgical site infection, by health professionals, after bariatric surgery, promoting improved care and patient safety in the perioperative period.


Introduction
Obesity is known as an epidemic disease with worldwide repercussions, recurrent in developed and developing countries, being one of the main risk factors for chronic non-communicable diseases, such as diabetes mellitus and cardiovascular diseases. This disease has multifactorial causes linked to environmental, economic, genetic, metabolic and lifestyle aspects. Through the Body Mass Index (BMI), the World Health Organization defines the diagnosis of obesity, that is, BMI ≥ 30 kg/m 2 (1)(2) .
Bariatric surgery is considered a therapeutic option for the treatment of obesity, when conservative clinical treatment (diet, physical exercises and medication) has not been successful and after careful evaluation by a multidisciplinary team. In addition to the nutritional status and physical conditions of the patient, the team must assess mental health, since the success of the surgery depends on changes in lifestyle, eating habits and the search for emotional balance of the individual who will undergo the procedure. In short, bariatric surgery leads to weight loss, with improvement in body parameters, as well as a reduction in morbidity and mortality associated with obesity (2)(3) .
Currently, in bariatric surgery, two types of procedures are the most chosen by surgeons, namely, sleeve gastrectomy and Roux-en-Y gastric bypass, which can be performed in open, laparoscopic approaches (minimally invasive surgery) or robotics (robot-assisted surgery) (4) .
Complications after bariatric surgery can be classified as early (during the immediate postoperative period) or late (generally, after 30 days postoperatively). Depending on the type of surgical procedure, early complications include hemorrhage, anastomotic leakage, gastric or small bowel perforation, and deep vein thrombosis/pulmonary embolism, and major late complications are bowel obstruction, gallstone formation, and gastrointestinal hemorrhage (5) .

Surgical site infection (SSI) is also a relevant
complication that can affect patients undergoing bariatric surgery, since obesity is a risk factor for the development of this type of infection (6)(7)(8) . In addition, patients with obesity are more susceptible to developing infectious diseases. However, the mechanisms underlying the Such factors include changes in respiratory physiology, changes in the skin and soft tissues, comorbidities such as type 2 diabetes mellitus and cardiovascular disease, drug therapy and, above all, underdosing of antimicrobials (8) .
The prevention and early treatment of complications are essential to achieve better results for the patient and, consequently, the success of the therapy. Thus, the performance of a multidisciplinary team is crucial, from the preparation for the surgery and the follow-up in the postoperative period. In this context, the nurse has a prominent role, since this professional is responsible for planning and implementing the necessary nursing care and for health education. In addition, they must have knowledge about complications after bariatric surgery, aimed at their prevention and early detection, effectively helping the patient's well-being and the new condition of life.
In view of the above, the synthesis of knowledge produced on SSI in bariatric surgery can help the multidisciplinary team, contributing to the improvement of care provided and patient safety, especially nursing care. Thus, the delimited objective of the present review was to evaluate the evidence on the risk factors for the development of surgical site infection in bariatric surgery.

Study type
The method of knowledge synthesis selected for conducting this study was the integrative review of the literature (IR). The steps covered were: elaboration of the review question, literature search of primary studies, evaluation of primary studies, data analysis and presentation of the review (9) .
The IR protocol was registered in the Open Science Framework (OSF). This platform is open, and the main objective is to support the conduct of research and allow collaboration between researchers, in a global context.

Setting
The IR was carried out in the city of Ribeirão Preto, São Paulo State, Brazil.

Study period
The study was carried out from March 2021 to March  In the CINAHL and LILACS databases, the search strategies adopted were similar, but using the base vocabulary (controlled descriptors), that is, CINAHL Headings and Health Science Descriptors (DeCS), respectively. In the databases, the final search strategies for publications were implemented on May 2, 2021.

Sample definition
The EndNote reference manager (version XII -Desktop) was used to remove duplicates of exported results (publications) from the four databases (10) .
The Rayyan platform was used for the selection of primary studies among the reviewers (11) . Thus, this

Data collection
To collect data from the studies included in the review, a script was built with the following items: authors; study title; year of publication; journal name; objective; sample and method detail; statistical analysis; data on the occurrence/incidence of SSI; main results and conclusion.
This step was carried out, from August to October 2021, by two reviewers, independently, and through meetings, differences were discussed until consensus.

Data processing and analysis
The identification of the type of study was according Institute. This international organization provides free tools for each type of study, that is, randomized clinical trial, quasi-experimental study, cohort study, crosssectional study, among others. Such tools are composed of questions, and for each one, the reviewer answers yes, www.eerp.usp.br/rlae 4 Rev. Latino-Am. Enfermagem 2023;31:e3798.
In Figures 2 and 3, the descriptive synthesis of the primary studies was presented, using the following information: authors and year of publication of the research, sample, type of study, objective(s) and risk factors for the development of SSI. In Figure 2, the primary studies grouped were those in which the target population underwent laparoscopic bariatric surgery.  no, uncertain or not applicable. Through these questions, the internal validity and risk of bias of the study are evaluated (selection of participants, method adopted and analysis of results) (12) .

The tool entitled JBI Critical Appraisal Checklist for
Studies Reporting Prevalence Data was used to evaluate prospective or retrospective studies. For the evaluation of cohort studies, the tool adopted is called JBI Critical Appraisal Checklist for Cohort Studies and, for case-control studies, the tool is called JBI Critical Appraisal Checklist Case Control Studies.
The evaluation of the methodological quality was carried out, in February 2022, by two reviewers, independently, and the divergences were discussed in meetings until consensus.
Data analysis and synthesis were performed in a descriptive manner.

Results
In Figure 1, the flowchart of the selection process of the primary studies included in the IR was presented.
Thus, of the 318 publications identified in the databases (registries), after applying the eligibility criteria, 36 primary studies were selected for full reading and 11 were part of the review sample.

Type of study/sample Objective (s) Risk factors
Ruiz-Tovar, et al. (2013) (14) Prospective study (authors) Sample: n=40 To investigate the association of comorbidities and pre and postoperative variables with surgical site infection after sleeve gastrectomy.  (15) Retrospective cohort study (authors) Sample: n=815 To quantify the rate of postoperative infection after bariatric surgery.
To determine whether infection-related events contribute to lengthening hospital stays and to assess the effect of risk factors, such as diabetes, on infection rates.
The authors did not analyze risk factors for SSI, but for general infection that occurred in the postoperative period.
(2017) (16) Retrospective study (authors) Sample: n=1,400 To assess whether a secondary, planned wound closure in the upper left abdomen reduces the rate of wound infection and whether such a technique has a positive impact on hospital stay, costs, and postoperative morbidity.
Women; primary wound closure; dyslipidemia and presence of preoperative gastritis (analytical statistical treatment) Meister, et al.
(2018) (17) Retrospective study (authors) Sample: n=1,981 To assess the significance of perioperative hyperglycemia in different complications of infection (six types of infection were investigated, including surgical site infection) and clinical outcomes.
In univariate analysis, perioperative hyperglycemia was associated with the development of SSI in patients with diabetes.
In the study there was no analysis of this nature.    (20) Prospective cohort study (authors) Sample: n=2,012 To assess the surgical site infection rate of group patients from community hospitals and compare with previously published rates of patients in tertiary hospitals.
Chopra, et al. (21) Case-control study (authors) Sample: n=751 To assess the importance of potential risk factors for surgical site infection after bariatric surgery.
Gerber, et al. (22) Cohort study (authors) Sample: n=47,660 Define the risk of complications and mortality in relation to age after gastric bypass. Age (analytical statistical treatment). To present a descriptive analysis of the results of a care package applied to obese patients undergoing bariatric surgery for infection control.
Body mass index; diabetes mellitus (correlation between variables).
Gray, et al.
(2020) (4) Retrospective study (authors) Sample: n=148,260 Explore the routine use of abdominal drain placement in sleeve gastrectomy and Roux-en-Y gastric bypass surgeries to assess associated complications and potential risk factors.
Drain (analytical statistical treatment). Coorth study Were the two groups similar and recruited from the same population?; † Q2 = Were exposures measured similarly to assign participants to exposed The JBI Critical Appraisal Checklist for Cohort Studies tool was used to evaluate the cohort studies (n=4). Of the 11 questions that make up the checklist, in two studies (15,22) , seven questions received the answer "yes", and in the other two (20,23) , six questions were also answered "yes" (Figure 5). Using the JBI Critical Appraisal Checklist Case Control Studies tool to evaluate the only case-control study included in the review, the survey received "yes" answers to all checklist questions (10 questions) (21) . In the methodological evaluation of the primary studies, the tools proposed by the Joanna Briggs Institute were used, and none of them have a scoring system for the general evaluation of the research, but it can be affirmed that a greater quantity of "yes" answers is indicative of better results. methodological quality (24) .
In the evaluation of prospective or retrospective studies (n=6), through the JBI Critical Appraisal Checklist for Studies Reporting Prevalence Data tool, of the nine questions that make up the checklist, in three researches (16)(17)(18) , eight questions received the answer "yes" in the evaluation carried out by the reviewers and in a study (14) , seven questions received the answer "yes" (Figure 4).  (19) .
In the literature, in a national cross-sectional study, In this grouping of primary studies included in the review, perioperative hyperglycemia (14,17) , female sex (16,18) and high BMI (14,18) were the risk factors investigated in at least two studies and confirmed by means of the statistical treatment used.
In a prospective cohort study, with a sample of 484 patients undergoing abdominal surgery, the defined objectives were to evaluate the independent effect of perioperative hyperglycemia and the incidence of SSI. (n=395) did not have this disease. The incidence of SSI was 20.25% (98/484), with hyperglycemia being an independent risk factor for this type of infection (26) .
In the literature, in a cross-sectional study whose
In the prospective study, the authors investigated the association of comorbidities and variables (pre and postoperatively) with SSI after sleeve gastrectomy. The sample consisted of 40 patients, and SSI was diagnosed in three patients (7.5%), two cases classified as organ/ space (intra-abdominal abscess) and one superficial (14) .
In the retrospective cohort study, patients underwent the following types of bariatric surgery: Roux-en-Y gastric bypass, sleeve gastrectomy and adjustable gastric band, with a sample of 815 patients.
The incidence of surgery-related infection was 4.2% in the first postoperative month (15) .
In the retrospective study, the sample consisted of 1,400 patients undergoing Roux-en-Y gastric bypass.
In this research, a surgical technique was tested (planned and tested) (p <0.001) (16) .
In another retrospective study, the sample consisted of 1,981 patients who underwent Roux-en-Y gastric bypass or sleeve gastrectomy, 38% (n=751) had diabetes and 62% (n=1,230) did not have diabetes. chronic disease.
Regarding SSI, in the group of patients without diabetes, the overall rate of superficial SSI was 0.7% (n=9) and organ/space SSI was 0.4% (n=5). In the group of patients with diabetes, the overall rate of superficial SSI was 2.8% (n=21) and of organ/space SSI was 0.9% (n=7) (17) .
In a retrospective study, the authors developed (OR=4.48) and a postoperative period of more than three days of hospitalization (OR= 5.03) (27) .
In a retrospective study with the participation of 772 patients who underwent Roux-en-Y gastric bypass or sleeve gastrectomy in a tertiary-level hospital in the United States of America, the objective was to identify risk factors for early complications in bariatric surgery.
The results showed that open surgery was associated with the occurrence of superficial and organ/space SSI, in comparison with the laparoscopic approach (30) .
Antibiotic prophylaxis (20)(21) was the only risk factor investigated in at least two studies included in the review and delimited in this grouping.  (31) .
Due to the current discussion about the use of drains in bariatric surgery, in the present review, only in one study, the device was the risk factor investigated (4) .
In a retrospective study, the authors defined the objective of identifying common preoperative characteristics that could have led to drain placement, surgical variables associated with drain placement, and The percentage of participants with a drain dropped from 33.1% to 24.6% in the study period and from 20.3% to 13.6%, respectively. The authors concluded that despite the reduction in the use of drains in bariatric surgery, the use of this device is still very common (33) .
Regarding the limitations of the integrative review, the inclusion of primary published studies was limited, that is, the gray literature was not considered, and there were restrictions on languages and period. Data analysis and synthesis were performed in a descriptive manner.
Thus, combining data from different types of studies is a challenging process that can lead to bias in the elaboration of review results.
On the other hand, the search for primary studies was carried out in the main health and nursing databases.
In addition, to assess the methodological quality of